US and Iowa state flags fly next to a corn field in Grand Mound, Iowa. Midwestern farmers have increased their vigilance ever since Mo Hailong and five other Chinese nationals were accused by US authorities in 2013 of digging up genetically modified corn seeds from Iowa farms and planning to send them back to China.

United States law enforcement agencies are a urging farmers and businesses more broadly to be increasingly vigilant amid a rise in attempted thefts of genetically engineered seed and other commercial secrets.

Mo Hailong, one of six Chinese nationals US authorities accused in 2013 of digging up seeds from Iowa farms with plans to send them back to China, pleaded guilty in January, according to Reuters. Mr. Mo had his case prosecuted by the Justice Department as a matter of national security rather than a normal criminal case.

The FBI and Justice Department has reported a growing number of agricultural espionage cases in the past two years, including government research facilities, companies and research facilities. While the FBI says it knows of connections between the accused individuals and the Chinese government, it does not have evidence to prove the link that would stand up in court. The Chinese government denies it is involved.

The trend particularly highlights how highly coveted and vulnerable advanced food technology secrets are, particularly in China where 1.36 billion of earth's roughly 7 billion person population lives, Reuters said. However, while the Chinese government has indicated it wants to be a leader in the biotechnology world, there is also evidence to suggest this may be stymied by Chinese consumer wariness about the yet unknown problems that could stem from the consumption of genetically modified food.

"Consumer resistance could present a major obstacle for President Xi Jinping, who wants China to be 'bold' in embracing biotechnology and transforming domestic farming. After decades of gains, crops yields in China have flattened, and the government fears becoming overly dependent on imported food if agriculture isn’t adequately modernized. They see engineered crops – mainly wheat, rice, and corn – as a way to increase productivity and possibly reduce use of fertilizers and pesticides," wrote Stuart Leavenworth for The Monitor earlier this year.

US senators recently called for a review of state-owned ChemChina’s $43 billion deal to buy Swiss seed group Syngenta, which generates nearly a quarter of its revenue from North America. From the Chinese government’s point of view, such a deal would ease its concerns that foreign companies would control the supply of GM food in China.

However, Carl Pray, a Rutgers University economist who specializes in Chinese agriculture, told the Monitor that "it may not ease the concerns of consumers who are largely focused on food safety."

Agribusiness giant Monsanto says if the Chinese were to acquire GMO seeds and recreate a corn plant it would allow Chinese companies to bypass around eight years of research, which costs the company roughly $1.5 billion per year, Reuters reported.